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Circum-Antarctic Paleobathymetry to 30° South: Present to 75my

This software package models the paleobathymetry of the circum-Antarctic oceans back to the Late Cretaceous. It is based on a revised tectonic model of the circum-Antarctic region, and incorporates features such as spatially variable subsidence rates, refined rotation poles and a detailed treatment of selected areas. 

The software output consists of color-coded maps at user-specified Cenozoic ages and the associated gridded paleobathymetry for all oceans lying south of 30°S.


Hayes, D.E., C. Zhang and R.A. Weissel (2009), Modeling Paleobathymetry in the Southern Ocean. Eos, Vol. 90, No. 19, 12 May 2009, p. 165-166. doi: 10.1029/2009EO190001

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Figure 1: Map of present day Antarctic bathymetry.

Data and Files


This model approximates the composite effects of sedimentation through loading and burial while assuming a constant sedimentation rate at each grid point. It differs from that of Brown, et al., 2006 because it does not assume uniform cooling-induced subsidence throughout the entire region being modelled.


There are many steps involved in reconstructing paleobathymetry for any specified time. First, plates are rotated back to their position at the target time and oceanic crust younger than the target age is removed. Next, the residual present-day bathymetry must be adjusted to account for the effects of crustal subsidence, sedimentation and eustatic sea level changes. In some places, crust that existed at the target age has since been subducted and must be resurrected.

The user may accept our default parameters or enter new values at runtime for parameters such as subsidence. The user may also alter basic input data such as bathymetry, crustal age, sediment thickness and stage poles by creating new files. See Appendix A for the required file formats.

Related Content

The Antarctic Paleobathymetry project draws heavily on the Marine Geophysical Atlas of the Circum-Antarctic to 30° S (Hayes, 1991):

  • Appendix A (PDF): Table I describes each Region, using the Region Number shown on the Tectonic Regions image on this page. The Stage Pole files are listed in Table II and are available as digital files accessed through this web page.
  • Appendix B (PDF), parts 1 & 2: Includes a description of input and output file formats and Table III, a comprehensive reference to plates, regions, program modules and reconstruction data files.
  • Appendix C (PDF): A processing overview and schematic diagram explaining modifications available to the user.

  • Images of Calculated Paleobathymetry: Image files are available for ages 1-10Ma in 1 my increments, and 10 - 75Ma in 5my increments.
  • Image Files of Input Data used: Bathymetry, crustal ages, sediment thickness, and plates and regions are shown in polar stereographic projection.
  • Stage Pole files: files containing the stage poles required to rotate each plate through time. (text)
  • Basefiles: These contain the bathymetry, crustal age and sediment thickness data at zero-age (Present) needed to process each geographic region. (text or binary)
  • Subsidence Rate (Cooling) and Sealevel files: Easily modified text files specify the subsidence and sea level history to be applied to each region.